In recent years, an electric automobile and a hybrid automobile, which have devices such as a motor and a battery mounted thereon and run by driving the motor with electric power stored in the battery, have begun to spread. Regarding an electric automobile, charging to a battery is achieved by power feeding from an outside feed device. Even regarding a hybrid automobile, a plug-in hybrid automobile, in which charging from an outside feed device to a battery can be performed, has come into practical use. It is to be noted that the outside feed device is a feed device, which is located in facilities such as an ordinary house or a commercial power feeding station. For power feeding from a feed device to a vehicle, a plug at a tip of a charging cable connected with the feed device is connected with a feeding port, which is placed in a vehicle as a power receiving connector. In addition, power feeding from the feed device via a feeder wire, which is included in the charging cable, to the vehicle is performed and the battery is charged.
It is to be noted that the charging cable includes not only the feeder wire but also other wiring such as a ground wire and a control wire. A control wire is a wiring, which is to be used for transmission of a control signal such as a control pilot signal to be used for power feeding control of an electric power storage device. By transmitting and receiving a control signal between a feed device and a vehicle via the control wire, various states such as a connection state of a charging cable, a state of the possibility of charging, and a state of charging are detected, and charge control corresponding to detected states is performed.
Furthermore, for practical application of an automobile such as an electric automobile or a hybrid automobile which requires power feeding from outside, demanded is a communication function to transmit and receive information, which is to be used for charge control, and communication information, which is to be used for management of charge amount or accounting or the like, between a vehicle and a feed device.
Therefore, standardization of communication such as inband communication for superimposing a communication signal on a control signal and transmitting and receiving an obtained signal between a vehicle and a feed device is being promoted (see “SURFACE VEHICLE RECOMMENDED PRACTICE”, J1772 January 2010, Society of Automotive Engineers, Inc., October 1996 (revised in January 2010), for example).
FIG. 11 is an explanatory drawing for illustrating a structure example of a system, standardization of which is being promoted. Denoted at 1000 in FIG. 11 is a vehicle, and the vehicle 1000 is connected with a charging cable 3000 for power feeding from a feed device 2000. The charging cable 3000 includes two feeder wires 3001 and 3002 to be used as electric power supply wires, a ground wire 3003 which is a lead for grounding, and a control wire 3004 configured to transmit a control signal such as a control pilot signal (CPLT) to be used for charge control.
One end of the charging cable 3000 is connected with a feed device 2000 side, and power feeding becomes possible by connecting a plug 3005, which is provided at the other end side, with a power receiving connector 1001, which is placed at a feeding port at a vehicle 1000 side as a connection part.
The feed device 2000 is provided with an electric power supply unit 2001 configured to supply AC electric power, a charge control unit 2002 configured to perform communication pertaining to charge control, a communication unit 2003 configured to transmit and receive a communication signal, and a superposition separation unit 2004 configured to superpose and separate the communication signal for the ground wire 3003 and the control wire 3004.
In addition, the superposition separation unit 2004 superposes various kinds of communication signals for the ground wire 3003 and the control wire 3004, and separates various kinds of superposed communication signals. Communication by the communication unit 2003 is achieved when the superposition separation unit 2004 superposes various kinds of communication signals outputted from the communication unit 2003 and inputs various kinds of separated communication signals to the communication unit 2003.
The vehicle 1000 is provided with the power receiving connector 1001, a battery 1002, a charging device 1003 configured to charge the battery 1002, a charge control device 1004 configured to perform communication pertaining to charge control, a communication device 1005 configured to transmit and receive a communication signal, and a superposition separation element 1006 configured to superpose and separate a communication signal for the ground wire 3003 and the control wire 3004.
In addition, the superposition separation element 1006 superposes various kinds of communication signals for the ground wire 3003 and the control wire 3004, and separates various kinds of superposed communication signals.
Communication by the communication device 1005 is achieved when the superposition separation element 1006 superposes various kinds of communication signals outputted from the communication device 1005 and inputs various kinds of separated communication signals to the communication device 1005.